EP0187138B1 - Microorganism and plasmid for the constitutive synthesis of creatine amidino hydrolase and method for their production - Google Patents

Microorganism and plasmid for the constitutive synthesis of creatine amidino hydrolase and method for their production Download PDF

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EP0187138B1
EP0187138B1 EP86100066A EP86100066A EP0187138B1 EP 0187138 B1 EP0187138 B1 EP 0187138B1 EP 86100066 A EP86100066 A EP 86100066A EP 86100066 A EP86100066 A EP 86100066A EP 0187138 B1 EP0187138 B1 EP 0187138B1
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plasmid
coli
fragment
pbt
pvu
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EP0187138A3 (en
EP0187138A2 (en
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Günter Dr. Schumacher
Peter Dr. Buckel
Klaus Dr. Beaucamp
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Roche Diagnostics GmbH
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Roche Diagnostics GmbH
Boehringer Mannheim GmbH
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    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12NMICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N9/00Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
    • C12N9/14Hydrolases (3)
    • C12N9/78Hydrolases (3) acting on carbon to nitrogen bonds other than peptide bonds (3.5)
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S435/00Chemistry: molecular biology and microbiology
    • Y10S435/8215Microorganisms
    • Y10S435/822Microorganisms using bacteria or actinomycetales
    • Y10S435/848Escherichia
    • Y10S435/849Escherichia coli
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S435/00Chemistry: molecular biology and microbiology
    • Y10S435/8215Microorganisms
    • Y10S435/822Microorganisms using bacteria or actinomycetales
    • Y10S435/874Pseudomonas
    • Y10S435/877Pseudomonas putida

Definitions

  • the enzyme creatinamidino-hydrolase EC 3.5.3.3 is used industrially to determine creatinine. It is therefore u. a. used in clinical analysis for the diagnosis of kidney diseases in which creatinine levels occur in the serum or urine which differ from those of the healthy organism.
  • microorganisms are known, such as, for example, Pseudomonas species which, under induction by creatine, are able to produce creatinamidino hydrolase in an amount which is worth the workup, the yields which can be achieved and the cost of isolating the enzyme are still a limiting factor represents the industrial application of the enzyme.
  • An object of the invention is therefore a microorganism of the genus E. coli or Pseudomonas putida, which is characterized in that it is transformed with a recombinant plasmid which contains DNA encoding creatinamidinohydrolase and constitutively forms creatinamidinohydrolase. No inductive formation of this enzyme has yet been found for microorganisms of the genus E. coli. In Pseudomonas putida there is information for the formation of creatinamidino hydrolase, but the enzyme is only formed under induction and in very low activities.
  • a preferred microorganism of the genus E. coli according to the invention contains the plasmid pBT 2a-1. Such a microorganism is able to provide up to 50% of its total protein synthesis power for the formation of creatinamidino hydrolase.
  • Another preferred microorganism according to the invention is that of the genus E. coli or Pseudomonas putida, which contains the plasmid pBT 306.16.
  • Such microorganisms are also constitutive creatinamidinohydrolase formers with a very high synthesis performance.
  • the invention also relates to the plasmids pBT 2a-1, DSM 3148P and pBT 306.16, DSM 3149P. While the first-mentioned plasmid delivers a particularly high synthesis performance in microorganisms of the genus E. coli, the second-mentioned plasmid has the advantage that it gives high expression of the desired enzyme both in the genus E. coli and in the genus Pseudomonas putida.
  • the information for the expression of the creatinamidino hydrolase is found on the 5.8 Kb fragment, or its subfragment of 2.2 Kb, which is cleaved out in the manner mentioned above with the restriction endonuclease Eco R1 alone or Eco R1 together with Pvu 11 becomes.
  • the respective fragments are cloned according to the methods known to the genetic engineer into a vector which has been cleaved with the same or the same restriction endonucleases in order to create suitable ends.
  • the plasmid pBR 322 is preferably used as the vector and, after inserting one of the two Pseudomonas putida DNA fragments, it is transformed into a suitable E. coli strain. Numerous E.
  • coli strains are known to the person skilled in the art and can be transformed very well with the plasmid pBR 322 and its derivatives.
  • Another preferred vector is the X-phage Charon 10.
  • pBR 322 and derivatives thereof, like X-vectors, are commercially available.
  • pBR 322 is cleaved with Eco R1 and Pvu 11, the 2.3 Kb fragment formed is isolated and linked to the 2.2 Kb Eco R1-Pvu 11 fragment from P. putida to form a new plasmid designated pBT 3-2, which is transformed into E. coli.
  • E. coli K12 ED 8654 DSM 3144 is thus obtained.
  • E. coli strains transformed with the plasmid derivative from pBR 322 described above can be selected very well on the basis of their ampicillin resistance. Since they are both ampicillin-resistant and creatinamidino hydrolase generator, non-transformed cells cannot grow and among the grown cells those which form the desired enzyme can easily be found using a method described in more detail below.
  • a screening system which makes it possible to identify formed microorganism clones with particularly high activity on creatinamidino hydrolase is obtained by contacting such clones with agarose plates which contain creatine, sarcosine oxidase, peroxidase and an H 2 0 2 color indicator system in solution. One then selects those clones for the multiplication which give the strongest coloration corresponding to the strongest enzyme formation.
  • the H 2 0 2 color indicator system used is preferably 4-aminoantipyrine in combination with N-ethyl-N- (sulfoethyl) -3-methylaniline salt, advantageously the potassium salt.
  • the method according to the invention can also be used to produce plasmids which are suitable not only for the expression of the enzyme in E. coli, but also in P. putida.
  • the procedure is preferably such that a 2.8 Kb fragment is obtained from pBT 2a-1 by cleavage with the restriction endonucleases Pvu I and Pvu 11 and this is ligated with a further 10 Kb fragment which is cleaved from pBT 306.1 Pvu I and Sma I is obtained.
  • the plasmid pBT 306.16, DSM 3149P is thus obtained, which causes the constitutive creatinamidino hydrolase formation in both E. coli and P. putida.
  • the information for a protein is contained in the deoxyribonucleic acid (DNA).
  • This DNA is translated into mRNA (messenger ribonucleic acid) by a DNA-dependent RNA polymerase.
  • mRNA messenger ribonucleic acid
  • the mRNA synthesized in this way is translated into protein on the ribosomes, with three nucleotides (triplet or codon) determining the incorporation of a particular amino acid according to the laws of the genetic code.
  • Control areas at the DNA level determine at which point a strand of the DNA is translated into mRNA (promoter sequences) or at which point the synthesis of the mRNA is stopped. (Termination sequence).
  • Stop and start sequences are also known at the level of protein synthesis (translation).
  • an ATG which is translated into f-methionine determines the start of a protein and e.g. B. a TAA or a TAG the end of translation.
  • the extent of expression of a polypeptide sequence depends on several factors: e.g. B. on the quality of the promoter sequence, mRNA stability, secondary and tertiary structure of the mRNA, quality of the ribosomal binding site, distance of the ribosomal binding site from the start codon (ATG), nucleotide sequence between the ribosomal binding site and start codon (ATG) and the presence of efficient stop signals Level of transcription and translation. Without precise knowledge of the primary structure of the gene and the protein encoded by it, it is not possible to intervene in a targeted manner in the regulatory processes of gene expression described above. Because this precise knowledge is not in the present case were present, the improved synthesis performance of the microorganisms and plasmids according to the invention could not be predicted.
  • Wild-type isolates but also laboratory strains can be used as host cells from the Pseudomonas putida strain. Particularly good results were achieved with Pseudomonas putida 2440, DSM 2106 (Gene 1981, 237-247).
  • the vector systems for expression in E. coli are preferably genetically manipulated derivatives of the commercially available plasmid pBR 322 (Gene 1977, 95-113).
  • Genetically modified derivatives of plasmid pRSF 1010 (Gene 1981, 237-247) are preferably used for expression in Pseudomonas strains.
  • restriction endonucleases for the construction of the genetically modified plasmids of the invention one obtains the gene segments coding the creatinamidinohydrolase, which still contains the expression vector system and a regulatory origin which brings about an increased copy number of the vector system in the host cell, as well as genes thereon Products can be easily selected (e.g. antibiotic resistance).
  • a screening system can be used according to the invention which works according to the principle of the enzyme immunoassay.
  • specific antibodies against the creatinamidino hydrolase are attached to a suitable carrier, e.g. B. fixed a polyvinyl film, the film is placed on lysed colonies or on plaques. After washing with H 2 0, the film is incubated with the same specific antibody in the form of an enzyme conjugate (e.g. with peroxidase). If there is a clone producing the enzyme, a sandwich of antibody-antigen and enzyme-labeled antibody is formed.
  • the antibody-peroxidase conjugate gives a staining in a suitable color indicator system, e.g. B. in an indicator system of tetramethylbenzidine, dioctyl sodium sulfosuccinate and H 2 0 2 in green gelatin spots.
  • a suitable color indicator system e.g. B. in an indicator system of tetramethylbenzidine, dioctyl sodium sulfosuccinate and H 2 0 2 in green gelatin spots.
  • This system results in a detection limit of 10 pg to 100 pg protein antigen.
  • the preparation of such an enzyme immunoassay and the preparation of suitable antibodies can be carried out according to the instructions for "Test combination gene expression" Boehringer Mannheim GmbH.
  • the chromosomal DNA from Pseudomonas putida DSM 2106 is isolated after lysis of the cells and winding of the DNA onto a glass rod and, after 2 phenolizations and ethanol precipitation, dissolved in a concentration of 600 ⁇ g / ml (Cosloy and Oishi, Molec. Gen. Genet., 1973, 124, 1-10).
  • the enzyme immunotest described above is used to identify phages which contain a gene encoding creatinase.
  • the indicator system consists of 6 mg / ml tetramethylbenzidine, 20 mg / ml dioctyl sodium sulfosuccinate and 0.01% H 2 0 2 in 6% gelatin. Two positive signals are found for every 1000 plaques.
  • Phage DNA was prepared from five plaques positive in the enzyme immunoassay, as previously described. In addition to different bands, cleavage of the five different DNAs with Eco RI showed a common DNA band in all five phage DNAs of 5.8 Kb. The 5.8 Kb fragment was characterized with different restriction nucleases (FIG. 1).
  • a 2.2 Kb fragment was cleaved from approximately 5 ⁇ g of this Eco RI fragment using Pvu II.
  • the resulting DNA fragments are separated according to their size in a low melting agarose gel and the 2.2 Kb Eco RI - Pvu II fragment is isolated.
  • DNA fragments are isolated from low-melting agarose gels by cutting out the corresponding band, transferring it to a test tube (Eppendor tube) and adding about twice the volume of water. Then incubate at 65 ° C.
  • the sample is shaken briefly and with half a volume of phenol (neutralized with 10 mM TRIS-HCl pH 7.5 and 1 mM EDTA, TE ) shaken vigorously.
  • the phases are separated by centrifugation at 15,000 g for 10 minutes and the upper aqueous phase is shaken again with phenol.
  • the upper phase is shaken twice with 1 ml of ether each time, the ether is evaporated at 65 ° C. and the DNA with 1/10 volume of 3 M Naacetate pH 7.2 and 2.5 times the volume of ethanol at -20 ° C.
  • the DNA is sedimented by centrifugation for 10 minutes at 15,000 g in a vacuum and taken up in 10 ⁇ l TE. All fragment isolations described further take place according to this procedure.
  • pBR 322 DNA are digested with Eco RI and Pvu II and a 2.3 Kb fragment is isolated. 0.2 ⁇ g of this pBR 322 fragment are incubated overnight using five units of T4 DNA ligase with 0.5 ⁇ g of the 2.2 Kb Eco RI-Pvull fragment from the previously described x phage. The resulting plasmid is called pBT 3-2 and encodes a biologically active creatinase in E. coli.
  • the DNA encoding creatinase from plasmid pBT 3-2 is treated exactly according to the method of Talmadge and Gilbert, Gene, 1980, 12, 235-241, during the amplification phase with nitrosoguanidine.
  • the plasmid DNA is then isolated after lysing the cells using the CsCI-ethidium bromide method (Maniatis et al., Molecular Cloning, Cold Spring Harbor 1982, 88-94). Competent cells of the strain E. coli ED 8654 are transformed with plasmid DNA (Maniatis et al., Molecular Cloning Cold Spring Harbor, 1982, 250-251) and plated on full medium plates (LB) containing 20 ⁇ g / ml ampicillin.
  • LB full medium plates
  • the colonies are stamped on LB plates onto which a nitrocellulose filter paper (Schleicher, Schüll BA 85) has been placed beforehand. After incubation of the plates for 12 to 18 hours at 37 ° C., the nitrocellulose filter with the colonies is lifted off and transferred to a glass petri dish (0 20 cm) into which 1 ml of chloroform / toluene (1: 1) was added. Incubation is carried out for 20 minutes at 37 ° C. The nitrocellulose filter is then placed on an indicator agarose plate so that there is direct contact between the cells and the indicator plate. The color reaction depends on the time and the amount of creatinase synthesized in each clone.
  • the clone ED with the plasmid pBT 2a-1, DSM 3143 is isolated from the activity screening described above.
  • This plasmid encodes a creatinase, which makes up about 50% of the soluble protein of the cells. This method is shown schematically in FIG. 1.
  • a third-party promoter e.g. B. the lactose promoter (this can be isolated, for example, from commercially available plasmids, such as, for example, the pUC plasmids, as a DNA fragment), an increase in the expression of creatinase can be obtained.
  • plasmid pBT 3-2 is opened at the EcoR1 site and treated with exonuclease Bal 31 so that approximately 10 to 100 bp are removed from each side. Then the lactose promoter is ligated into the shortened plasmid pBT 3-2 with the aid of the enzyme T 4 ligase, with ends being linked.
  • This DNA is then, as described above, mutagenized with nitroso-guanidine, then used for the transformation of the ED strain and the clones are tested for high gene expression in the described plate screening.
  • the above-mentioned indicator agarose plate represents a test system for an activity screening, the principle of which consists in creating the H 2 0 2 formed from creatine by the enzymes creatinamidino hydrolase and sarcosine oxidase via peroxidase (POD) in 1/2 0 2 and H 2 0 to split and the oxygen with the color indicator system z.
  • the reagents listed under 1 to 7 are dissolved and mixed with the same volume of low-melting agarose (2%). 6 ml are poured into a Petri dish, the plates can be stored in the dark at 4 ° C for approx. 2 weeks.
  • Plasmid RSF 1010 (Bagdasarian et al., Gene 1981, 16, 237-247) is used for cloning and expression of the cloned creatinamidino hydrolase in Pseudomonas putida.
  • RSF 1010 was linearized with Pvu II and the 1.4 Kb fragment was isolated from plasmid pACYC 177 (Chang and Cohen, J. Bacteriol., 1978 134, 1141-1156) after Hae II cleavage.
  • 0.2 ⁇ g RSF 1010 DNA was linked to 1 ⁇ g of the Hae II fragment using T4 ligase, the resulting plasmid is pBT 306.1 (Fig. 2).
  • RSF 1010 and derivatives of this plasmid are characterized by a wide host range (Gene, 16 (1981) 237-247) and are e.g. B. suitable to amplify both in pseudomonas and in E. coli.
  • Plasmid pBT 2a-1 was digested with Pvu I and Pvu II and the 2.8 Kb fragment was isolated, pBT 306.1 was digested with Pvu I and Sma I and the 10 Kb fragment was isolated.
  • 0.5 ⁇ g of the vector DNA is ligated with 0.5 ⁇ g of the Pvul-Pvull fragment.
  • E. coli ED is transformed and clones encoding creatinase are identified using the plate activity screening previously described.
  • Plasmid DNA is prepared from one of the positive clones using the previously described CsCI-ethidium bromide method. The plasmid is called pBT 306.16, DSM 3149 P (Fig. 3).
  • the creatinamidino hydrolase activity is determined by detecting the ammonium ions formed in the reaction sequence with urease using the test combination "urea" (Boehringer Mannheim, order no. 124770).
  • the wild type Pseudomonas putida 2440 is incubated at 30 ° C. overnight in LB medium (5 ml) containing 1% creatine to determine the creatinamidino hydrolase activity.
  • the cells are harvested by centrifugation and washed once in 50 mM phosphate buffer pH 7.5.
  • the cells are taken up in their original volume in phosphate buffer (50 mM pH 7.5) and disrupted by ultrasound treatment (4 x 30 seconds).
  • Cells containing a plasmid encoding creatinamidino hydrolase are grown and disrupted in the same manner as described above, except that the medium contains no creatine for induction and that the plasmid is added by adding ampicillin (20 ⁇ g / ml for plasmid pBT 3-2, pBT 2a-1) or streptomycin (200 ⁇ g / ml for plasmid pBT 306.16) is selected. Cultures grow at 30 ° C for Pseudomonas putida and at 37 ° C for E. coli.
  • the activity is 500 units / g biomass (moist) or the specific activity is 4.5 U / mg protein. Since the spec. Activity of the highly purified protein is 9 U / mg, this means that the creatinamidino hydrolase in E. coli accounts for 50% of the soluble protein. Analysis of a crude extract in the SDS gel (Laemmli, Nature, 1970, 227, 680-685) shows that the creatinamidino hydrolase is the main band of the soluble protein fraction (FIG. 4, column 2).
  • E. coli host systems namely E. coli W 3350, E. coli ED 8654 and E. coli CSH 1, were used for the cultivation in the fermenter.
  • the plasmid pBT 2a-1 is transformed into the corresponding competent cells.
  • DYT medium iller, Experiments in Molecular Genetics, Cold Spring Harbor, 1972, 433
  • the fermentation medium (DYT) is mixed with the Inoculated pre-culture (inoculum 1%) and growing for 20 to 30 hours without selection for plasmid preservation at 37 ° C.
  • the creatinamidino hydrolase activity is approximately 600 U / g wet weight or 4.5 U / mg protein.
  • the plasmid pBT 306.16 is transformed into competent cells of the strain 2440 as previously described, whereby PS putida DSM 3147 is obtained.
  • a preculture is incubated in DYT medium containing 200 ⁇ g / ml streptomycin at 30 ° C. overnight.
  • the fermentation medium (DYT) is inoculated (inoculum 1%) and the culture is allowed to grow at 30 ° C. for 20 to 30 hours.
  • the activity after 25 hours is approx. 220 U / g wet weight or 1.8 U / mg protein.

Abstract

The present invention provides a micro-organism of the species Escherichia coli or Pseudomonas putida, wherein it constitutively forms creatinamidinohydrolase. The present invention also provides a process for the production of such a micro-organism.

Description

Das Enzym Creatinamidino-Hydrolase EC 3.5.3.3 findet industriell Anwendung zur Creatininbestimmung. Es wird daher u. a. in der klinischen Analytik für die Diagnose von Nierenerkrankungen verwendet, bei welchen im Serum oder im Urin Creatiningehalte auftreten, die von denen des gesunden Organismus abweichen. Zwar sind Mikroorganismen bekannt, wie beispielsweise Pseudomonas-Arten, welche unter Induktion durch Creatin in der Lage sind, Creatinamidino-Hydrolase in einer die Aufarbeitung lohnenden Menge herzustellen, die erzielbaren Ausbeuten und die Kosten der Isolierung des Enzyms stellen jedoch immer noch einen limitierenden Faktor für die industrielle Anwendung des Enzyms dar.The enzyme creatinamidino-hydrolase EC 3.5.3.3 is used industrially to determine creatinine. It is therefore u. a. used in clinical analysis for the diagnosis of kidney diseases in which creatinine levels occur in the serum or urine which differ from those of the healthy organism. Although microorganisms are known, such as, for example, Pseudomonas species which, under induction by creatine, are able to produce creatinamidino hydrolase in an amount which is worth the workup, the yields which can be achieved and the cost of isolating the enzyme are still a limiting factor represents the industrial application of the enzyme.

Es besteht daher ein Bedarf an Mikroorganismen, welche diese Nachteile nicht aufweisen und insbesondere die Creatinamidinohydrolase konstitutiv bilden, d. h. ohne daß hierzu eine Induktion erforderlich ist, und dabei wesentlich bessere Ausbeuten liefern als die bisher bekannten Creatinamidino-Hydrolasebildner. Weiter ist es ein Ziel der Erfindung, nach den Methoden der Gentechnologie einen derartigen Mikroorganismus herzustellen, bei welchem die genetische Information für eine hohe Syntheseleistung an dem angegebenen Enzym in einem Wirtsmikroorganismus vorliegt, der sich gut züchten läßt und aus dem sich das Enzym kostengünstig isolieren läßt.There is therefore a need for microorganisms which do not have these disadvantages and in particular form the creatinamidinohydrolase constitutively, i.e. H. without induction being required for this, and at the same time providing significantly better yields than the creatinamidino hydrolase formers known hitherto. It is a further object of the invention to produce such a microorganism according to the methods of genetic engineering, in which the genetic information for a high synthesis performance on the specified enzyme is present in a host microorganism which can be grown well and from which the enzyme can be isolated inexpensively .

Erfindungsgemäß gelingt es, diese Aufgabe zu lösen. Ein Gegenstand der Erfindung ist daher ein Mikroorganismus der Gattung E. coli oder Pseudomonas putida, welcher dadurch gekennzeichnet ist, daß er mit einem rekombinanten Plasmid transformiert ist, welches Creatinamidinohydrolase kodierende DNA enthält und konstitutiv Creatinamidinohydrolase bildet. FÜr Mikroorganismen der Gattung E. coli ist eine auch induktive Bildung dieses Enzyms bisher nicht gefunden worden. Bei Pseudomonas putida ist zwar eine Information für die Bildung von Creatinamidino-Hydrolase vorhanden, das Enzym wird jedoch nur unter Induktion gebildet und in recht niedrigen Aktivitäten.According to the invention, this task can be solved. An object of the invention is therefore a microorganism of the genus E. coli or Pseudomonas putida, which is characterized in that it is transformed with a recombinant plasmid which contains DNA encoding creatinamidinohydrolase and constitutively forms creatinamidinohydrolase. No inductive formation of this enzyme has yet been found for microorganisms of the genus E. coli. In Pseudomonas putida there is information for the formation of creatinamidino hydrolase, but the enzyme is only formed under induction and in very low activities.

Ein bevorzugter Mikroorganismus der Gattung E. coli gemäß der Erfindung enthält das Plasmid pBT 2a-1. Ein derartiger Mikroorganismus ist in der Lage, bis zu 50% seiner gesamten Syntheseleistung an Protein für die Bildung von Creatinamidino-Hydrolase aufzubringen.A preferred microorganism of the genus E. coli according to the invention contains the plasmid pBT 2a-1. Such a microorganism is able to provide up to 50% of its total protein synthesis power for the formation of creatinamidino hydrolase.

Ein weiterer bevorzugter Mikroorganismus gemäß der Erfindung ist ein solcher der Gattung E. coli oder Pseudomonas putida, welcher das Plasmid pBT 306.16 enthält. Derartige Mikroorganismen sind ebenfalls konstitutive Creatinamidinohydrolasebildner mit sehr hoher Syntheseleistung.Another preferred microorganism according to the invention is that of the genus E. coli or Pseudomonas putida, which contains the plasmid pBT 306.16. Such microorganisms are also constitutive creatinamidinohydrolase formers with a very high synthesis performance.

Ein weiterer Gegenstand der Erfindung sind die Plasmide pBT 2a-1, DSM 3148P und pBT 306.16, DSM 3149P. Während das erstgenannte Plasmid eine besonders hohe Syntheseleistung in Mikroorganismen der Gattung E. coli liefert, besitzt das zweitgenannte Plasmid den Vorteil, daß es sowohl in der Gattung E. coli, als auch in der Gattung Pseudomonas putida eine hohe Expression des gewünschten Enzyms ergibt.The invention also relates to the plasmids pBT 2a-1, DSM 3148P and pBT 306.16, DSM 3149P. While the first-mentioned plasmid delivers a particularly high synthesis performance in microorganisms of the genus E. coli, the second-mentioned plasmid has the advantage that it gives high expression of the desired enzyme both in the genus E. coli and in the genus Pseudomonas putida.

Wie bereits erwähnt, lassen sich die erfindungsgemäßen Mikroorganismen bzw. Plasmide nach Methoden der Gentechnologie gewinnen. So besteht das erfindungsgemäße Verfahren zur Herstellung von konstitutiv Creatinamidino-Hydrolase bildenden Mikroorganismen der genannten Gattungen darin, daß man DNA aus Pseudomonas putida

  • a) mit Eco R I limitiert verdaut und ein 5,8 Kb-Bruchstück gewinnt oder
  • b) mit Eco R1 und Pvu 11 spaltet und ein 2,2 Kb-Bruchstück gewinnt,
das nach a) oder b) erhaltene Bruchstück in einen mit dem bzw. den gleichen Restriktionsendonukleasen gespaltenen Vektor kloniert, diesen in einen für den gewählten Vektor geeigneten E. coli oder P. putida Stamm transformiert und die konstitutiv Creatinamidinohydrolase bildenden Klone isoliert. Kb steht hier für "Kilobasenpaar", also tausend Nukleotidbasenpaare.As already mentioned, the microorganisms or plasmids according to the invention can be obtained by methods of genetic engineering. Thus, the method according to the invention for the production of constitutive creatinamidino hydrolase-forming microorganisms of the genera mentioned is that DNA from Pseudomonas putida
  • a) digested with Eco RI limited and a 5.8 Kb fragment wins or
  • b) split with Eco R1 and Pvu 11 and win a 2.2 Kb fragment,
the fragment obtained according to a) or b) is cloned into a vector cleaved with the same or the same restriction endonucleases, this is transformed into an E. coli or P. putida strain suitable for the selected vector and the clones constitutively forming creatinamidinohydrolase are isolated. Kb stands for "kilobase pair", ie a thousand nucleotide base pairs.

Die Information für die Expression der Creatinamidino-Hydrolase findet sich auf dem 5,8 Kb-Bruchstück, bzw. dessen Unterfragment von 2,2 Kb, welches in der oben erwähnten Weise mit der Restriktionsendonuklease Eco R1 alleine oder Eco R1 zusammen mit Pvu 11 herausgespalten wird. Die jeweiligen Fragmente werden nach den dem Gentechniker bekannten Methoden in einen Vektor kloniert, der mit der gleichen bzw. den gleichen Restriktionsendonukleasen gespalten wurde, um passende Enden zu schaffen. Alternativ, wenn auch nicht bevorzugt, ist es auch möglich, für E. coli oder Pseudomonas putida geeignete Vektoren mit anderen Restriktionsendonukleasen zu spalten, deren Spaltungsstellen am speziellen Vektor so angeordnet sind, daß die Replikationsfähigkeit des an der Spaltungsstelle mit einem der oben erwähnten DNA-Bruchstücke aus Pseudomonas putida ergänzten Vektors und seine Transformierbarkeit in einen Wirtsstamm aufrechterhalten bleibt. Als Vektor verwendet man vorzugsweise das Plasmid pBR 322 und transformiert dieses nach dem Einfügen eines der beiden Pseudomonas putida DNA-Fragmente in einen geeigneten E. coli Stamm. Dem Fachmann sind zahlreiche E. coli Stämme bekannt, die sich mit dem Plasmid pBR 322 und seinen Derivaten sehr gut transformieren lassen. Ein anderer bevorzugter Vektor ist der X-Phage Charon 10. pBR 322 sowie Derivate desselben sind ebenso wie X-Vektoren kommerziell erhältlich.The information for the expression of the creatinamidino hydrolase is found on the 5.8 Kb fragment, or its subfragment of 2.2 Kb, which is cleaved out in the manner mentioned above with the restriction endonuclease Eco R1 alone or Eco R1 together with Pvu 11 becomes. The respective fragments are cloned according to the methods known to the genetic engineer into a vector which has been cleaved with the same or the same restriction endonucleases in order to create suitable ends. Alternatively, although not preferred, it is also possible to cleave vectors suitable for E. coli or Pseudomonas putida with other restriction endonucleases, the cleavage sites of which are arranged on the special vector in such a way that the replication ability of the cleavage site with one of the above-mentioned DNA Fragments from Pseudomonas putida supplemented vector and its transformability into a host strain is maintained. The plasmid pBR 322 is preferably used as the vector and, after inserting one of the two Pseudomonas putida DNA fragments, it is transformed into a suitable E. coli strain. Numerous E. coli strains are known to the person skilled in the art and can be transformed very well with the plasmid pBR 322 and its derivatives. Another preferred vector is the X-phage Charon 10. pBR 322 and derivatives thereof, like X-vectors, are commercially available.

Mehr bevorzugt wird ein Verfahren, bei dem man pBR 322 mit Eco R1 und Pvu 11 spaltet, das dabei gebildete 2,3 Kb-Fragment isoliert und mit dem 2,2 Kb Eco R1-Pvu 11 Fragment aus P. putida verknüpft unter Bildung eines als pBT 3-2 bezeichneten neuen Plasmids, welches man in E. coli transformiert. Man erhält so E. coli K12 ED 8654 DSM 3144.More preferred is a method in which pBR 322 is cleaved with Eco R1 and Pvu 11, the 2.3 Kb fragment formed is isolated and linked to the 2.2 Kb Eco R1-Pvu 11 fragment from P. putida to form a new plasmid designated pBT 3-2, which is transformed into E. coli. E. coli K12 ED 8654 DSM 3144 is thus obtained.

In der obenbeschriebenen Weise mit dem Plasmidderivat aus pBR 322 transformierte E. coli Stämme lassen sich sehr gut aufgrund ihrer Ampicillinresistenz selektieren. Da sie sowohl ampicillinresistent als auch Creatinamidino-Hydrolasebildner sind, können nicht transformierte Zellen nicht anwachsen und unter den angewachsenen Zellen lassen sich leicht diejenigen, welche das gewünschte Enzym bilden, nach einer weiter unten näher beschriebenen Methode herausfinden.E. coli strains transformed with the plasmid derivative from pBR 322 described above can be selected very well on the basis of their ampicillin resistance. Since they are both ampicillin-resistant and creatinamidino hydrolase generator, non-transformed cells cannot grow and among the grown cells those which form the desired enzyme can easily be found using a method described in more detail below.

Besonders gute Ergebnisse erhält man erfindungsgemäß, wenn man die pBT 3-2 enthaltenden transformierten E. coli Zellen zum Zeitpunkt der Amplifikation des Plasmides mit Nitrosoguanidin behandelt, danach das Plasmid daraus isoliert, erneut in E. coli Zellen transformiert, diesen Zyklus gegebenenfalls wiederholt und aus den dabei erhaltenen Mikroorganismusklonen mit besonders ausgeprägter Creatinamidino-Hydrolase-Aktivität das Plasmid pBT 2a-1, DSM 3148P, welches ebenfalls einen Gegenstand der Erfindung darstellt, gewinnt. Wie oben bereits erwähnt, produzieren E. coli Zellen, welche dieses Plasmid enthalten, bis zu 50% an Creatinamidino-Hydrolase, bezogen auf ihre gesamte Proteinbildung.Particularly good results are obtained according to the invention if the transformed E. coli cells containing pBT 3-2 are treated with nitrosoguanidine at the time of amplification of the plasmid, then the plasmid is isolated therefrom, transformed again into E. coli cells, and this cycle is repeated if necessary and out the resulting microorganism clones with particularly pronounced creatinamidino hydrolase activity, the plasmid pBT 2a-1, DSM 3148P, which is also an object of the invention, wins. As mentioned above, E. coli cells containing this plasmid produce up to 50% of creatinamidino hydrolase based on their total protein formation.

Ein Screeningsystem, welches es gestattet, gebildete Mikroorganismenklone mit besonders hoher Aktivität an Creatinamidino-Hydrolase zu identifizieren, erhält man, indem man derartige Klone mit Agaroseplatten kontaktiert, welche Creatin, Sarcosinoxidase, Peroxidase und ein H202-Farbindikatorsystem gelöst enthalten. Man wählt dann diejenigen Klone für die Vermehrung aus, welche die stärkste Färbung entsprechend der stärksten Enzymbildung ergeben. Als H202-Farbindikatorsystem wird bevorzugt 4-Aminoantipyrin in Kombination mit N-Ethyl-N-(sulfoethyl)-3-methylanilinsalz, zweckmäßig das Kaliumsalz, verwendet.A screening system which makes it possible to identify formed microorganism clones with particularly high activity on creatinamidino hydrolase is obtained by contacting such clones with agarose plates which contain creatine, sarcosine oxidase, peroxidase and an H 2 0 2 color indicator system in solution. One then selects those clones for the multiplication which give the strongest coloration corresponding to the strongest enzyme formation. The H 2 0 2 color indicator system used is preferably 4-aminoantipyrine in combination with N-ethyl-N- (sulfoethyl) -3-methylaniline salt, advantageously the potassium salt.

Mit dem erfindungsgemäßen Verfahren lassen sich auch Plasmide herstellen, die nicht nur zur Expression des Enzyms in E. coli, sondern auch in P. putida geeignet sind. Vorzugsweise verfährt man hierfür so, daß man aus pBT 2a-1 durch Spaltung mit den Restriktionsendonukleasen Pvu I und Pvu 11 ein 2,8 Kb-Fragment gewinnt und dieses mit einem weiteren, 10 Kb-Fragment ligiert, welches aus pBT 306.1 durch Spaltung mit Pvu I und Sma I erhalten wird. Man erhält so das Plasmid pBT 306.16, DSM 3149P, welches die konstitutive Creatinamidino-Hydrolase-Bildung sowohl in E. coli als auch in P. putida bewirkt.The method according to the invention can also be used to produce plasmids which are suitable not only for the expression of the enzyme in E. coli, but also in P. putida. For this purpose, the procedure is preferably such that a 2.8 Kb fragment is obtained from pBT 2a-1 by cleavage with the restriction endonucleases Pvu I and Pvu 11 and this is ligated with a further 10 Kb fragment which is cleaved from pBT 306.1 Pvu I and Sma I is obtained. The plasmid pBT 306.16, DSM 3149P is thus obtained, which causes the constitutive creatinamidino hydrolase formation in both E. coli and P. putida.

Es ist überraschend, daß erfindungsgemäß eine wesentliche Erhöhung der Enzymbildung erreicht wird. Es wurde nämlich zwar schon mehrfach berichtet, daß durch die Anwendung der Methoden der DNA-Neukombination durch Erhöhung der Kopienzahl eines bestimmten Gens eine gesteigerte Genexpression gelungen ist. Es kann jedoch nicht davon ausgegangen werden, daß die Übertragung von Genen aus Pseudomonas in E. coli mit Wahrscheinlichkeit zu einer Erhöhung der Genexpression führt. Tatsächlich ist sogar für die Mehrzahl der durch DNA-Neukombination aus Pseudomonas in E. coli übertragene Gene eine Reduktion der Genexpression berichtet worden (vgl. z. B. Stanisisch und Ortiz, J. Gen. Microbiol., 1976, 94, 281-289, Nakazawa et al., J. Bacteriol., 1978, 134, 270-277, Ribbons et al., Soc. Gen. Microbiol., Quart., 1978, 6, 24-25, Franklin et al., in Microbiol Degradation of Xenobiotics and Recalcitrant Compounds, Leisinger Cook, Hütter und Nuesch Hrsgb., 1981, 109-130). Daß eine derartige Verbesserung nicht erwartet werden kann, zeigt eine Betrachtung der verschiedenen biologischen Syntheseschritte, die ablaufen müssen, bis endlich ein enzymatisch aktives Protein gebildet wird.It is surprising that, according to the invention, a substantial increase in enzyme formation is achieved. Indeed, it has been reported several times that the use of new recombination methods by increasing the number of copies of a particular gene has increased gene expression. However, it cannot be assumed that the transfer of genes from Pseudomonas to E. coli is likely to lead to an increase in gene expression. In fact, a reduction in gene expression has been reported even for the majority of genes transferred from Pseudomonas DNA recombination in E. coli (see, e.g., Stanisisch and Ortiz, J. Gen. Microbiol., 1976, 94, 281-289 , Nakazawa et al., J. Bacteriol., 1978, 134, 270-277, Ribbons et al., Soc. Gen. Microbiol., Quart., 1978, 6, 24-25, Franklin et al., In Microbiol Degradation of Xenobiotics and Recalcitrant Compounds, Leisinger Cook, Hütter and Nuesch ed., 1981, 109-130). That such an improvement cannot be expected is shown by a consideration of the various biological synthesis steps that have to take place until an enzymatically active protein is finally formed.

Die Information für ein Protein ist in der Desoxyribonucleinsäure (DNA) enthalten. Diese DNA wird durch eine DNA-abhängige RNA-Polymerase in mRNA (Boten ribonucleinsäure) übersetzt. Die so synthetisierte mRNA wird an den Ribosomen in Protein übersetzt, dabei bestimmen jeweils drei Nucleotide (Triplett oder Codon) - nach den Gesetzen des genetischen Codes - den Einbau einer bestimmten Aminosäure.The information for a protein is contained in the deoxyribonucleic acid (DNA). This DNA is translated into mRNA (messenger ribonucleic acid) by a DNA-dependent RNA polymerase. The mRNA synthesized in this way is translated into protein on the ribosomes, with three nucleotides (triplet or codon) determining the incorporation of a particular amino acid according to the laws of the genetic code.

Kontrollbereiche auf DNA-Ebene bestimmen, an welcher Stelle ein Strang der DNA in mRNA übersetzt wird (Promotorsequenzen) bzw. an welcher Stelle die Synthese der mRNA gestoppt wird. (Terminationssequenz).Control areas at the DNA level determine at which point a strand of the DNA is translated into mRNA (promoter sequences) or at which point the synthesis of the mRNA is stopped. (Termination sequence).

Stopp- und Startsequenzen sind ebenso auf der Ebene der Proteinsynthese (Translation) bekannt. Dabei bestimmt im allgemeinen ein ATG (das in f-Methionin übersetzt wird) den Beginn eines Proteins und z. B. ein TAA oder ein TAG das Ende der Translation.Stop and start sequences are also known at the level of protein synthesis (translation). In general, an ATG (which is translated into f-methionine) determines the start of a protein and e.g. B. a TAA or a TAG the end of translation.

Das Ausmaß der Expression einer Polypeptidsequenz ist von mehreren Faktoren abhängig: z. B. u. a. von der Qualität der Promotorsequenz, mRNA-Stabilität, Sekundär- und Tertiärstruktur der mRNA, Qualität der ribosomalen Bindungsstelle, Abstand der ribosomalen Bindungsstelle vom Startcodon (ATG), Nucleotidsequenz zwischen ribosomaler Bindungsstelle und Startcodon (ATG) und dem Vorhandensein effizienter Stoppsignale auf Transskriptions- und Translationsebene. Ohne genaue Kenntnis der Primärstruktur des Gens und des von diesem kodierten Proteins kann nicht gezielt in die oben beschriebenen Regulationsprozesse der Genexpression eingegriffen werden. Da diese genauen Kenntnisse im vorliegenden Falle nicht vorhanden waren, konnte die verbesserte Syntheseleistung der erfindungsgemäßen Mikroorganismen und Plasmide nicht vorhergesehen werden.The extent of expression of a polypeptide sequence depends on several factors: e.g. B. on the quality of the promoter sequence, mRNA stability, secondary and tertiary structure of the mRNA, quality of the ribosomal binding site, distance of the ribosomal binding site from the start codon (ATG), nucleotide sequence between the ribosomal binding site and start codon (ATG) and the presence of efficient stop signals Level of transcription and translation. Without precise knowledge of the primary structure of the gene and the protein encoded by it, it is not possible to intervene in a targeted manner in the regulatory processes of gene expression described above. Because this precise knowledge is not in the present case were present, the improved synthesis performance of the microorganisms and plasmids according to the invention could not be predicted.

Im Rahmen der vorliegenden Erfindung werden als E. coli vorteilhaft Derivate des E. coli K12-Stammes verwendet. Unter diesen wurden beispielsweise erfolgreich eingesetzt:

  • E. coli K12, W 3350 (thi, galK, galT, rpsl, von P. Tiollais), DSM 3141
  • E. coli K12, ED 8654 (trp R, hsd M , hsd R-, sup E, sup F, von K. Murray), DSM 2102
  • E. coli K12, CSH 1 (thi, trp, lac z, rpsl aus Cold Spring Harbor Stammsammlung), DSM 3142
In the context of the present invention, derivatives of the E. coli K12 strain are advantageously used as E. coli. Among them, for example, were successfully used:
  • E. coli K12, W 3350 (thi, galK, galT, rpsl, from P. Tiollais), DSM 3141
  • E. coli K12, ED 8654 (trp R, hsd M, hsd R-, sup E, sup F, from K. Murray), DSM 2102
  • E. coli K12, CSH 1 (thi, trp, lac z, rpsl from Cold Spring Harbor strain collection), DSM 3142

Als Wirtszellen vom Pseudomonas putida Stamm können Wildtypisolate aber auch Laborstämme eingesetzt werden. Besonders gute Ergebnisse wurden erzielt mit Pseudomonas putida 2440, DSM 2106 (Gene 1981, 237-247).Wild-type isolates but also laboratory strains can be used as host cells from the Pseudomonas putida strain. Particularly good results were achieved with Pseudomonas putida 2440, DSM 2106 (Gene 1981, 237-247).

Als Vektorsysteme für die Expression in E. coli werden erfindungsgemäß, wie erwähnt, vorzugsweise genetisch manipulierte Derivate des handelsüblichen Plasmids pBR 322 (Gene 1977, 95-113) verwendet. Für die Expression in Pseudomonas-Stämmen werden vorzugsweise genetisch abgewandelte Derivate des Plasmids pRSF 1010 (Gene 1981, 237-247) verwendet. Bei Verwendung der oben angegebenen Restriktionsendonukleasen für die Konstruktion der genetisch abgewandelten Plasmide der Erfindung erhält man die Creatinamidinohydrolase kodierende Genabschnitte, welche noch das Expressions-Vektor-System und einen Regulationsursprung, der eine erhöhte Kopienzahl des Vektorsystems in der Wirtszelle bewirkt, sowie Gene, auf deren Produkte leicht selektioniert werden kann (z. B. Antibiotika-Resistenzen) enthalten.As mentioned, according to the invention, the vector systems for expression in E. coli are preferably genetically manipulated derivatives of the commercially available plasmid pBR 322 (Gene 1977, 95-113). Genetically modified derivatives of plasmid pRSF 1010 (Gene 1981, 237-247) are preferably used for expression in Pseudomonas strains. Using the above-mentioned restriction endonucleases for the construction of the genetically modified plasmids of the invention one obtains the gene segments coding the creatinamidinohydrolase, which still contains the expression vector system and a regulatory origin which brings about an increased copy number of the vector system in the host cell, as well as genes thereon Products can be easily selected (e.g. antibiotic resistance).

Im Nachstehenden wird die Erfindung in Verbindung mit der Zeichnung und den Beispielen näher beschrieben. In der Zeichnung stellen dar:

  • Fig. 1 eine schematische Darstellung der Herstellung des Plasmids pBT 3-2 unter Verwendung des 2,2 Kb-Fragments aus der Pseudomonas putida DNA und des Plasmids pBR 322 als Ausgangsmaterial.
  • Fig. 2 zeigt die erfindungsgemäße Herstellung des Plasmids pBT 306.1 aus den Plasmiden RSF 1010 und pACYC 177 und
  • Fig. 3 zeigt die Bildung des erfindungsgemäßen Plasmids pBT 306.16 aus pBT 306.1 und pBT 2a-1 schematisch.
  • Fig. 4 zeigt ein SDS Gel, in dem Zellextrakte aufgetragen sind, von Spalte 1: Ausgangsstamm Pseudomonas putida, Spalte 2: dem das Plasmid pBT 2a-1 tragenden E. coli Wirtsstamm ED, Spalte 4: Wirtsstamm ED und Spalte 3: zum Vergleich 15 µg der gereinigten Creatinase.
  • Fig. 5 zeigt die das Enzym Creatinamidinohydrolase kodierende DNA-Sequenz und die aus der DNA-Sequenz resultierende Proteinsequenz.
The invention is described in more detail below in conjunction with the drawing and the examples. In the drawing:
  • Fig. 1 is a schematic representation of the preparation of the plasmid pBT 3-2 using the 2.2 Kb fragment from the Pseudomonas putida DNA and the plasmid pBR 322 as the starting material.
  • 2 shows the production according to the invention of the plasmid pBT 306.1 from the plasmids RSF 1010 and pACYC 177 and
  • 3 schematically shows the formation of the plasmid pBT 306.16 according to the invention from pBT 306.1 and pBT 2a-1.
  • 4 shows an SDS gel in which cell extracts are applied, from column 1: starting strain Pseudomonas putida, column 2: the E. coli host strain ED carrying the plasmid pBT 2a-1, column 4: host strain ED and column 3: for comparison 15 µg of the purified creatinase.
  • 5 shows the DNA sequence encoding the enzyme creatinamidinohydrolase and the protein sequence resulting from the DNA sequence.

Um positive Klone, d. h. Mikroorganismenklone, welche konstitutiv Creatinamidinohydrolase bilden, herauszufinden, kann erfindungsgemäß ein Screening-System eingesetzt werden, welches nach dem Prinzip des Enzymimmunotests arbeitet. Hierbei werden spezifische Antikörper gegen die Creatinamidino- Hydrolase an einen geeigneten Träger, z. B. eine Polyvinyl-Folie fixiert, die Folie wird auf lysierte Kolonien oder auch auf Plaques aufgelegt. Nach Waschen mit H20 wird die Folie mit dem gleichen spezifischen Antikörper in Form eines Enzymkonjugats (z. B. mit Peroxidase) inkubiert. Liegt ein das Enzym produzierender Klon vor, so entsteht ein Sandwich aus Antikörper-Antigen und enzymmarkiertem Antikörper.In order to find out positive clones, ie microorganism clones which constitutively form creatinamidinohydrolase, a screening system can be used according to the invention which works according to the principle of the enzyme immunoassay. Here, specific antibodies against the creatinamidino hydrolase are attached to a suitable carrier, e.g. B. fixed a polyvinyl film, the film is placed on lysed colonies or on plaques. After washing with H 2 0, the film is incubated with the same specific antibody in the form of an enzyme conjugate (e.g. with peroxidase). If there is a clone producing the enzyme, a sandwich of antibody-antigen and enzyme-labeled antibody is formed.

Das Antikörper-Peroxidase- Konjugat gibt in einem geeigneten Farbindikatorsystem eine Färbung, z. B. bei einem Indikatorsystem aus Tetramethylbenzidin, Dioctylnatriumsulfosuccinat und H202 in Gelatine grüne Farbflecken. Dieses System ergibt eine Nachweisgrenze von 10 pg bis 100 pg Proteinantigen. Die Herstellung eines derartigen Enzymimmunotests und die Präparation geeigneter Antikörper kann nach der Anleitung zu "Testkombination Genexpression" Boehringer Mannheim GmbH, erfolgen.The antibody-peroxidase conjugate gives a staining in a suitable color indicator system, e.g. B. in an indicator system of tetramethylbenzidine, dioctyl sodium sulfosuccinate and H 2 0 2 in green gelatin spots. This system results in a detection limit of 10 pg to 100 pg protein antigen. The preparation of such an enzyme immunoassay and the preparation of suitable antibodies can be carried out according to the instructions for "Test combination gene expression" Boehringer Mannheim GmbH.

Die folgenden Beispiele erläutern die Erfindung weiter.The following examples further illustrate the invention.

Beispiel 1example 1 A) Isolierung der Chromosomalen Pseudomonas putida DNAA) Isolation of the chromosomal Pseudomonas putida DNA

Die chromosomale DNA von Pseudomonas putida DSM 2106 wird nach Lyse der Zellen und Aufwickeln der DNA auf einen Glasstab isoliert und nach 2 Phenolisierungen und Ethanolfällung in einer Konzentration von 600 ug/ml gelöst (Cosloy und Oishi, Molec. Gen. Genet., 1973, 124, 1-10).The chromosomal DNA from Pseudomonas putida DSM 2106 is isolated after lysis of the cells and winding of the DNA onto a glass rod and, after 2 phenolizations and ethanol precipitation, dissolved in a concentration of 600 µg / ml (Cosloy and Oishi, Molec. Gen. Genet., 1973, 124, 1-10).

10 ug chromosomale DNA werden limitiert mit 5 Einheiten Eco RI, E.C. 3.1.23.11, 30 Minuten gespalten und das Ausmaß der Verdauung im Agarose Gel analysiert.10 µg of chromosomal DNA are limited with 5 units of Eco RI, E.C. 3.1.23.11, split for 30 minutes and analyzed the extent of digestion in the agarose gel.

B) Isolierung und Reinigung von Charon 10 DNAB) Isolation and purification of Charon 10 DNA

1010 Bakterien des Stammes E. coli ED DSM 2102 werden mit 5x108 x Phagen Charon 10 für 20 Minuten bei 37 °C inkubiert und anschließend bis zum Beginn der Lyse der Bakterien in 500 ml Vollmedium wachsen gelassen. Die Prozedur der Phagen- und DNA-Isolierung erfolgte exakt nach der Vorschrift von Maniatis et al., in: Molecular Cloning, Cold Spring Harbor Laboratory, 1982, 76-85.10 10 bacteria of the strain E. coli ED DSM 2102 are incubated with 5x10 8 x phage Charon 10 for 20 minutes at 37 ° C. and then left to grow in 500 ml complete medium until the lysis of the bacteria begins. The phage and DNA isolation procedure followed exactly the same Regulation of Maniatis et al., In: Molecular Cloning, Cold Spring Harbor Laboratory, 1982, 76-85.

10 µg Charon 10 DNA werden vollständig mit Eco RI gespalten. 1 µg limitiert mit Eco RI verdaute chromosomale Pseudomonas putida DNA gemäß A) wird mit 3 µg mit Eco RI gespaltener Charon 10 DNA mit 40 Einheiten des Enzyms T4 DNA Ligase inkubiert. Das Verpacken der zusammenligierten DNA-Fragmente in Kopf- und Schwanzproteine des Phagen erfolgt im Reagenzglas. Die Herstellung der zur Verpackung notwendigen Proteine sowie die Verpackung der DNA erfolgt nach Maniatis et al., Molecular Cloning, Cold Spring Harbor Laboratory 1982, 256-291 (in vitro Verpackungssysteme für X DNA Partikel sind kommerziell erhältlich, z. B. Boehringer Mannheim, "DNA-Packaging Kit"). Ca. 0,5 µg der zusammengeknüpften und Pseudomonas putida DNA wurden mit 20 µl des in vitro Verpackungsansatzes inkubiert, nach 60 Minuten werden 0,5 ml SM Puffer (Maniatis et al., Cold Spring Harbor Laboratory 1982, 443) zugegeben und 1/200 Volumen (2,5 µl) des Verpakkungsansatzes mit 200 µl einer Übernachtkultur des Stammes ED (in 10-2 M Magnesiumsulfat) für 10 Minuten bei 37°C inkubiert. Die Bakteriensuspension wird anschließend mit 3 ml LB (Miller in Experiments in Molecular Genetics, Cold Spring Harbor Laboratory 1972 433) Agarose (0,8%) gemischt und auf LB Platten gegossen. Pro 1 µg eingesetzter DNA werden ca. 105 Phagenlöcher (Plaques) erhalten.10 µg Charon 10 DNA are completely cleaved with Eco RI. 1 µg of chromosomal Pseudomonas putida DNA digested with Eco RI according to A) is incubated with 3 µg of Charon 10 DNA digested with Eco RI with 40 units of the enzyme T4 DNA ligase. The packaging of the ligated DNA fragments in head and tail proteins of the phage is done in a test tube. The proteins necessary for packaging and the packaging of the DNA are produced according to Maniatis et al., Molecular Cloning, Cold Spring Harbor Laboratory 1982, 256-291 (in vitro packaging systems for X DNA particles are commercially available, e.g. Boehringer Mannheim, "DNA Packaging Kit"). Approx. 0.5 µg of the linked and Pseudomonas putida DNA were incubated with 20 µl of the in vitro packaging batch, after 60 minutes 0.5 ml of SM buffer (Maniatis et al., Cold Spring Harbor Laboratory 1982, 443) was added and 1/200 volume (2.5 ul) of the Verpakkungsansatzes with 200 ul of an overnight culture of the strain ED (in 10- 2 M magnesium sulphate) for 10 minutes at 37 ° C. The bacterial suspension is then mixed with 3 ml of LB (Miller in Experiments in Molecular Genetics, Cold Spring Harbor Laboratory 1972 433) agarose (0.8%) and poured onto LB plates. About 10 5 phage holes (plaques) are obtained per 1 µg of DNA used.

Zur Identifizierung von Phagen, die ein Creatinase kodierendes Gen enthalten, wird der vorher beschriebene Enzym-Immunotest verwendet. Das Indikatorsystem besteht aus 6 mg/ml Tetramethylbenzidin, 20 mg/ml Dioctylnatriumsulfosuccinat und 0,01 % H202 in 6%iger Gelatine. Pro 1000 Plaques werden zwei positive Signale festgestellt.The enzyme immunotest described above is used to identify phages which contain a gene encoding creatinase. The indicator system consists of 6 mg / ml tetramethylbenzidine, 20 mg / ml dioctyl sodium sulfosuccinate and 0.01% H 2 0 2 in 6% gelatin. Two positive signals are found for every 1000 plaques.

C) Reklonierung des Creatinase-Gens in E. coliC) Recloning the creatinase gene in E. coli

Von fünf im Enzymimmunotest positiven Plaques wurde, wie vorher beschrieben, Phagen-DNA präpariert. Spaltung der fünf verschiedenen DNAs mit Eco RI zeigten neben unterschiedlichen Banden eine gemeinsame DNA-Bande in allen fünf Phagen DNAs von 5,8 Kb. Das 5,8 Kb große Fragment wurde mit verschiedenen Restriktionsnukleasen charakterisiert (Fig. 1).Phage DNA was prepared from five plaques positive in the enzyme immunoassay, as previously described. In addition to different bands, cleavage of the five different DNAs with Eco RI showed a common DNA band in all five phage DNAs of 5.8 Kb. The 5.8 Kb fragment was characterized with different restriction nucleases (FIG. 1).

Aus ca. 5 µg dieses Eco RI Fragments wurde unter Verwendung von Pvu II ein 2,2 Kb Fragment gespalten. Die entstehenden DNA Fragmente werden in einem niedrig schmelzenden Agarosegel nach ihrer Größe getrennt und das 2,2 Kb Eco RI - Pvu II Fragment isoliert. Die Isolierung von DNA-Fragmenten aus niedrigschmelzenden Agarosegelen erfolgt, indem die entsprechende Bande ausgeschnitten, in ein Reagenzglas (Eppendorfröhrchen) überführt und mit etwa dem zweifachen Volumen Wasser versetzt wird. Anschließend wird so lange bei 65 ° C inkubiert (5 bis 10 Minuten) bis die Agarose geschmolzen ist, die Probe wird kurz geschüttelt und mit einem halben Volumen Phenol (neutralisiert mit 10 mM TRIS-HCI pH 7,5 und 1 mM EDTA, TE) kräftig geschüttelt. Die Phasen werden durch Zentrifugation für 10 Minuten bei 15 000 g getrennt und die obere wäßrige Phase erneut mit Phenol ausgeschüttelt. Nach einer Zentrifugation von 10 Minuten bei 15 000 g wird die obere Phase zweimal mit je 1 ml Ether ausgeschüttelt, der Ether bei 65 ° C abgedampft und die DNA mit 1/10 Volumen 3 M Naacetat pH 7,2 und 2,5fachen Volumen Ethanol bei -20 ° C gefällt. Die DNA wird durch Zentrifugation für 10 Minuten bei 15 000 g sedimentiert im Vakuum getrocknet und in 10 µl TE aufgenommen. Alle weiter beschriebenen Fragmentisolierungen erfolgen nach dieser Prozedur.A 2.2 Kb fragment was cleaved from approximately 5 µg of this Eco RI fragment using Pvu II. The resulting DNA fragments are separated according to their size in a low melting agarose gel and the 2.2 Kb Eco RI - Pvu II fragment is isolated. DNA fragments are isolated from low-melting agarose gels by cutting out the corresponding band, transferring it to a test tube (Eppendor tube) and adding about twice the volume of water. Then incubate at 65 ° C. (5 to 10 minutes) until the agarose has melted, the sample is shaken briefly and with half a volume of phenol (neutralized with 10 mM TRIS-HCl pH 7.5 and 1 mM EDTA, TE ) shaken vigorously. The phases are separated by centrifugation at 15,000 g for 10 minutes and the upper aqueous phase is shaken again with phenol. After centrifugation at 15,000 g for 10 minutes, the upper phase is shaken twice with 1 ml of ether each time, the ether is evaporated at 65 ° C. and the DNA with 1/10 volume of 3 M Naacetate pH 7.2 and 2.5 times the volume of ethanol at -20 ° C. The DNA is sedimented by centrifugation for 10 minutes at 15,000 g in a vacuum and taken up in 10 μl TE. All fragment isolations described further take place according to this procedure.

Ca. 4 µg pBR 322 DNA werden mit Eco RI und Pvu II gespalten und ein 2,3 Kb Fragment isoliert. 0,2 µg dieses pBR 322 Fragments werden über Nacht unter Verwendung von fünf Einheiten T4 DNA Ligase mit 0,5 µg des 2.2 Kb Eco RI-Pvull Fragments aus dem vorher beschriebenen x Phagen inkubiert. Das resultierende Plasmid trägt die Bezeichnung pBT 3-2 und kodiert in E. coli eine biologisch aktive Creatinase.Approx. 4 µg pBR 322 DNA are digested with Eco RI and Pvu II and a 2.3 Kb fragment is isolated. 0.2 µg of this pBR 322 fragment are incubated overnight using five units of T4 DNA ligase with 0.5 µg of the 2.2 Kb Eco RI-Pvull fragment from the previously described x phage. The resulting plasmid is called pBT 3-2 and encodes a biologically active creatinase in E. coli.

Beispiel 2Example 2

Die Creatinase codierende DNA aus Plasmid pBT 3-2 wird exakt nach der Methode von Talmadge und Gilbert, Gene, 1980, 12, 235-241, während der Amplifikationsphase mit Nitrosoguanidin behandelt. Anschließend wird die Plasmid-DNA nach Lyse der Zellen über die CsCI-Ethidiumbromid Methode isoliert (Maniatis et al., Molecular Cloning, Cold Spring Harbor 1982, 88-94). Kompetente Zellen des Stammes E. coli ED 8654 werden mit Plasmid DNA transformiert (Maniatis et al., Molecular Cloning Cold Spring Harbor, 1982, 250-251) und auf Vollmediumplatten (LB) die 20 ug/ml Ampicillin enthalten, ausplattiert. Nach Inkubation über Nacht bei 37° C werden die Kolonien auf LB Platten gestempelt, auf die zuvor ein Nitrocellulose Filterpapier (Schleicher, Schüll BA 85) aufgelegt wurde. Nach Bebrütung der Platten für 12 bis 18 Stunden bei 37 ° C wird der Nitrocellulosefilter mit den Kolonien abgehoben und in eine Glaspetrischale (0 20 cm) überführt, in die 1 ml Chloroform/Toluol (1:1) gegeben wurde. Inkubation erfolgt für 20 Minuten bei 37° C. Der Nitrocellulosefilter wird anschließend auf eine Indikator-Agaroseplatte so aufgelegt, daß ein direkter Kontakt zwischen Zellen und Indikatorplatte entsteht. Die Farbreaktion erfolgt in Abhängigkeit von der Zeit und der Menge der in den einzelnen Klonen synthetisierten Creatinase. Aus dem oben beschriebenen Aktivitätsscreening wird der Klon ED mit dem Plasmid pBT 2a-1, DSM 3143 isoliert. Dieses Plasmid kodiert eine Creatinase, die ca. 50% des löslichen Proteins der Zellen ausmacht. Dieses Verfahren zeigt Fig. 1 schematisch.The DNA encoding creatinase from plasmid pBT 3-2 is treated exactly according to the method of Talmadge and Gilbert, Gene, 1980, 12, 235-241, during the amplification phase with nitrosoguanidine. The plasmid DNA is then isolated after lysing the cells using the CsCI-ethidium bromide method (Maniatis et al., Molecular Cloning, Cold Spring Harbor 1982, 88-94). Competent cells of the strain E. coli ED 8654 are transformed with plasmid DNA (Maniatis et al., Molecular Cloning Cold Spring Harbor, 1982, 250-251) and plated on full medium plates (LB) containing 20 µg / ml ampicillin. After overnight incubation at 37 ° C., the colonies are stamped on LB plates onto which a nitrocellulose filter paper (Schleicher, Schüll BA 85) has been placed beforehand. After incubation of the plates for 12 to 18 hours at 37 ° C., the nitrocellulose filter with the colonies is lifted off and transferred to a glass petri dish (0 20 cm) into which 1 ml of chloroform / toluene (1: 1) was added. Incubation is carried out for 20 minutes at 37 ° C. The nitrocellulose filter is then placed on an indicator agarose plate so that there is direct contact between the cells and the indicator plate. The color reaction depends on the time and the amount of creatinase synthesized in each clone. The clone ED with the plasmid pBT 2a-1, DSM 3143 is isolated from the activity screening described above. This plasmid encodes a creatinase, which makes up about 50% of the soluble protein of the cells. This method is shown schematically in FIG. 1.

Alternativ zu der hier beschriebenen direkten NG-Mutagenese kann auch durch Einfügung eines Fremdpromotors, z. B. des Lactosepromotors (dieser kann z. B. aus kommerziell erhältlichen Plasmiden, wie z. B. den pUC-Plasmiden, als DNA-Fragment isoliert werden), eine Expressionssteigerung der Creatinase erhalten werden. Dazu wird Plasmid pBT 3-2 an der EcoR1-Stelle geöffnet, mit der Exonuclease Bal 31 so behandelt, daß ca. 10 bis 100 Bp von jeder Seite entfernt werden. Dann wird der Lactose-Promotor mit Hilfe des Enzyms T4-Ligase, unter Verknüpfung der Enden, in das verkürzte Plasmid pBT 3-2 einligiert. Diese DNA wird dann, wie oben beschrieben, mit Nitroso-Guanidin mutagenisiert, anschließend für die Transformation des Stammes ED verwendet und die Klone werden in dem beschriebenen Plattenscreening auf hohe Genexpression getestet.As an alternative to the direct NG mutagenesis described here, it is also possible to insert a third-party promoter, e.g. B. the lactose promoter (this can be isolated, for example, from commercially available plasmids, such as, for example, the pUC plasmids, as a DNA fragment), an increase in the expression of creatinase can be obtained. For this, plasmid pBT 3-2 is opened at the EcoR1 site and treated with exonuclease Bal 31 so that approximately 10 to 100 bp are removed from each side. Then the lactose promoter is ligated into the shortened plasmid pBT 3-2 with the aid of the enzyme T 4 ligase, with ends being linked. This DNA is then, as described above, mutagenized with nitroso-guanidine, then used for the transformation of the ED strain and the clones are tested for high gene expression in the described plate screening.

Die vorstehend erwähnte Indikator-Agaroseplatte stellt ein Testsystem für ein Aktivitätsscreening dar, dessen Prinzip darin besteht, aus Creatin durch die Enzyme Creatinamidino-Hydrolase und Sarcosinoxidase das gebildete H202 über Peroxidase (POD) in 1/2 02 und H20 zu spalten und den Sauerstoff mit dem Farbindikatorsystem z. B. aus 4-Aminoantipyrin (4-AAP) und N-Ethyl-N-(sulfoethyl)-3-methylanilin, K-Salz (EST) reagieren zu lassen. Es entsteht eine blau-violette Färbung, die bei Überschuß der Enzyme Sarcosinoxidase und Peroxidase ein Maß für in den Kolonien synthetisierte Creatinamidino-Hydrolase darstellt.

Figure imgb0001
Zusammensetzung des Creatinamidino-Hydrolase Aktivitätsscreening Systems
Figure imgb0002
The above-mentioned indicator agarose plate represents a test system for an activity screening, the principle of which consists in creating the H 2 0 2 formed from creatine by the enzymes creatinamidino hydrolase and sarcosine oxidase via peroxidase (POD) in 1/2 0 2 and H 2 0 to split and the oxygen with the color indicator system z. B. from 4-aminoantipyrine (4-AAP) and N-ethyl-N- (sulfoethyl) -3-methylaniline, K salt (EST) to react. The result is a blue-violet color which, when the enzymes sarcosine oxidase and peroxidase are in excess, is a measure of creatinamidino hydrolase synthesized in the colonies.
Figure imgb0001
Composition of the Creatinamidino-Hydrolase activity screening system
Figure imgb0002

Die unter 1 bis 7 angegebenen Reagenzien werden gelöst und mit gleichem Volumen niedrig schmelzender Agarose (2%) gemischt. 6 ml werden in eine Petrischale gegossen, die Platten können ca. 2 Wochen bei 4°C in der Dunkelheit gelagert werden.The reagents listed under 1 to 7 are dissolved and mixed with the same volume of low-melting agarose (2%). 6 ml are poured into a Petri dish, the plates can be stored in the dark at 4 ° C for approx. 2 weeks.

Beispiel 3Example 3

Zur Klonierung und Expression der klonierten Creatinamidino- Hydrolase im Pseudomonas putida wird Plasmid RSF 1010 (Bagdasarian et al., Gene 1981, 16, 237-247) verwendet. RSF 1010 wurde mit Pvu II linearisiert und aus Plasmid pACYC 177 (Chang und Cohen, J. Bacteriol., 1978 134, 1141-1156) nach Hae II Spaltung das 1,4 Kb Fragment isoliert. 0,2 µg RSF 1010 DNA wurden mit 1 ug des Hae II Fragments unter Verwendung von T4 Ligase verknüpft, das resultierende Plasmid ist pBT 306.1 (Fig. 2). RSF 1010 und Derivate dieses Plasmids zeichnen sich durch einen weiten Wirtsbereich aus (Gene, 16 (1981) 237-247) und sind z. B. geeignet, sich sowohl in Pseudomonaden als auch in E. coli zu amplifizieren. Plasmid pBT 2a-1 wurde mit Pvu I und Pvu II gespalten und das 2,8 Kb Fragment isoliert, pBT 306.1 wird mit Pvu I und Sma I gespalten und das 10 Kb Fragment isoliert. 0,5 µg der Vektor DNA wird mit 0,5 µg des Pvul-Pvull Fragments ligiert. E. coli ED wird transformiert und Creatinase kodierende Klone werden mit Hilfe des vorher beschriebenen Platten-Aktivitätsscreenings identifiziert. Von einem der positiven Klone wird nach der vorher beschriebenen CsCI - Ethidiumbromid Methode Plasmid DNA präpariert. Das Plasmid trägt die Bezeichnung pBT 306.16, DSM 3149 P (Fig. 3).Plasmid RSF 1010 (Bagdasarian et al., Gene 1981, 16, 237-247) is used for cloning and expression of the cloned creatinamidino hydrolase in Pseudomonas putida. RSF 1010 was linearized with Pvu II and the 1.4 Kb fragment was isolated from plasmid pACYC 177 (Chang and Cohen, J. Bacteriol., 1978 134, 1141-1156) after Hae II cleavage. 0.2 µg RSF 1010 DNA was linked to 1 µg of the Hae II fragment using T4 ligase, the resulting plasmid is pBT 306.1 (Fig. 2). RSF 1010 and derivatives of this plasmid are characterized by a wide host range (Gene, 16 (1981) 237-247) and are e.g. B. suitable to amplify both in pseudomonas and in E. coli. Plasmid pBT 2a-1 was digested with Pvu I and Pvu II and the 2.8 Kb fragment was isolated, pBT 306.1 was digested with Pvu I and Sma I and the 10 Kb fragment was isolated. 0.5 µg of the vector DNA is ligated with 0.5 µg of the Pvul-Pvull fragment. E. coli ED is transformed and clones encoding creatinase are identified using the plate activity screening previously described. Plasmid DNA is prepared from one of the positive clones using the previously described CsCI-ethidium bromide method. The plasmid is called pBT 306.16, DSM 3149 P (Fig. 3).

Die Transformation von Plasmid DNA in Pseudomonas putida 2440 erfolgt exakt nach der Methode von Franklin et al. in: Microbiol Degradation of Xenobiotics and Recalcitrant Compounds, Leisinger, Cook, Hütter und Nuesch, Hrgsb., 1981, 109-130. Mit Hilfe des Plattenaktivitätsscreenings wurden positive Klone identifiziert. Dies ist bei Pseudomonas putida 2440 - obwohl dieser Stamm eine chromosomal kodierte Creatinamidino-Hydrolase enthält - möglich, da die Expression der Plasmid-kodierten Creatinamidino- Hydrolase konstitutiv erfolgt. Dieses Unterscheidungsmerkmal erlaubt es, zwischen chromosomal-kodierter und plasmid-kodierter Creatinamidino-Hydrolase zu diskriminieren.The transformation of plasmid DNA into Pseudomonas putida 2440 takes place exactly according to the method of Franklin et al. in: Microbiol Degradation of Xenobiotics and Recalcitrant Compounds, Leisinger, Cook, Hütter and Nuesch, Hrgsb., 1981, 109-130. Positive clones were identified using plate activity screening. This is possible with Pseudomonas putida 2440 - although this strain contains a chromosomally coded creatinamidino hydrolase - because the expression of the plasmid-coded creatinamidino hydrolase is constitutive. This distinguishing feature makes it possible to discriminate between chromosomal-encoded and plasmid-encoded creatinamidino hydrolase.

Beispiel 4Example 4

Die Bestimmung der Creatinamidino-Hydrolase-Aktivität erfolgt über den Nachweis der in der Reaktionsfolge mit Urease gebildeten Ammoniumionen mit der Testkombination "Harnstoff" (Boehringer Mannheim, Best. Nr. 124770).The creatinamidino hydrolase activity is determined by detecting the ammonium ions formed in the reaction sequence with urease using the test combination "urea" (Boehringer Mannheim, order no. 124770).

Der Wildtyp Pseudomonas putida 2440 wird zur Bestimmung der Creatinamidino-Hydrolase-Aktivität in LB Medium (5 ml), das 1 % Creatin enthält, bei 30 °C über Nacht inkubiert. Die Zellen werden durch Zentrifugation geerntet und einmal in 50 mM Phosphatpuffer pH 7,5 gewaschen. Die Zellen werden im ursprünglichen Volumen in Phosphatpuffer (50 mM pH 7,5) aufgenommen und durch Ultraschallbehandlung (4 x 30 Sekunden) aufgeschlossen. Anzucht und Aufschluß von Zellen, die ein Creatinamidino-Hydrolase kodierendes Plasmid enthalten, erfolgt in gleicher Weise, wie oben beschrieben, mit der Ausnahme, daß das Medium kein Creatin zur Induktion enthält und daß auf das Plasmid durch Zugabe von Ampicillin (20 ug/ml für Plasmid pBT 3-2, pBT 2a-1) bzw. Streptomycin (200 ug/ml für Plasmid pBT 306.16) selektioniert wird. Das Wachstum der Kulturen erfolgt für Pseudomonas putida bei 30 ° C, für E. coli bei 37 ° C.The wild type Pseudomonas putida 2440 is incubated at 30 ° C. overnight in LB medium (5 ml) containing 1% creatine to determine the creatinamidino hydrolase activity. The cells are harvested by centrifugation and washed once in 50 mM phosphate buffer pH 7.5. The cells are taken up in their original volume in phosphate buffer (50 mM pH 7.5) and disrupted by ultrasound treatment (4 x 30 seconds). Cells containing a plasmid encoding creatinamidino hydrolase are grown and disrupted in the same manner as described above, except that the medium contains no creatine for induction and that the plasmid is added by adding ampicillin (20 µg / ml for plasmid pBT 3-2, pBT 2a-1) or streptomycin (200 µg / ml for plasmid pBT 306.16) is selected. Cultures grow at 30 ° C for Pseudomonas putida and at 37 ° C for E. coli.

Creatinamidino-Hydrolase in Pseudomonas putida und E. coli

Figure imgb0003
Creatinamidino hydrolase in Pseudomonas putida and E. coli
Figure imgb0003

Die Daten zeigen, daß durch die Klonierung der Creatinamidino-Hydrolase 1). E. coli Bakterien die neue Eigenschaft erhalten Creatinamidino-Hydrolase zu synthetisieren und 2). diese Expression - im Gegensatz zum Ausgangsstamm Pseudomonas putida - sowohl für E. coli wie für Pseudomonas putida konstitutiv erfolgt. Des weiteren ist zu entnehmen, daß durch Mutagenese der Creatinamidino-Hydrolase kodierenden DNA eine besonders hohe Expression erzielt werden kann. (Erhöhung der Liter-Aktivität gegenüber dem nicht induzierten Ausgangsstamm, bei Pseudomonas Faktor 1800, bei E. coli Faktor 2800).The data show that by cloning the creatinamidino hydrolase 1). E. coli bacteria get the new property to synthesize creatinamidino hydrolase and 2). this expression - in contrast to the parent strain Pseudomonas putida - is constitutive for both E. coli and Pseudomonas putida. It can also be seen that a particularly high expression can be achieved by mutagenesis of the DNA encoding creatinamidino hydrolase. (Increase in liter activity compared to the non-induced starting strain, with Pseudomonas factor 1800, with E. coli factor 2800).

In E. coli ED/pBT 2a-1 DSM 3143 beträgt die Aktivität 500 Einheiten/g Biomasse (feucht) bzw. die spezifische Aktivität 4,5 U/mg Protein. Da die spez. Aktivität des hochgereinigten Proteins 9 U/mg beträgt, heißt das, daß die Creatinamidino-Hydrolase in E. coli 50 % des löslichen Proteins ausmacht. Analyse eines Rohextrakts im SDS-Gel (Laemmli, Nature, 1970, 227, 680-685) zeigt, daß die Creatinamidino-Hydrolase die Hauptbande der löslichen Proteinfraktion darstellt (Fig. 4, Spalte 2).In E. coli ED / pBT 2a-1 DSM 3143, the activity is 500 units / g biomass (moist) or the specific activity is 4.5 U / mg protein. Since the spec. Activity of the highly purified protein is 9 U / mg, this means that the creatinamidino hydrolase in E. coli accounts for 50% of the soluble protein. Analysis of a crude extract in the SDS gel (Laemmli, Nature, 1970, 227, 680-685) shows that the creatinamidino hydrolase is the main band of the soluble protein fraction (FIG. 4, column 2).

Beispiel 5Example 5

Für die Kultivierung im Fermenter wurden drei verschiedene E. coli-Wirtsysteme, nämlich E. coli W 3350, E. coli ED 8654 bzw. E. coli CSH 1 verwendet. Das Plasmid pBT 2a-1 wird in die entsprechenden kompetenten Zellen transformiert. Nach Reinigung auf Einzelkolonien wird eine Vorkultur in DYT Medium (Miller, Experiments in Molecular Genetics, Cold Spring Harbor, 1972, 433) das 20 ug/ml Ampicillin enthält, über Nacht bei 37"C angezogen. Das Fermentationsmedium (DYT) wird mit der Vorkultur beimpft (Inocculum 1 %) und ohne Selektion auf Plasmiderhalt 20 bis 30 Stunden bei 37 ° C wachsen lassen. Die Creatinamidino-Hydrolase-Aktivität beträgt nach 25 Stunden ca. 600 U/g Feuchtmasse bzw. 4,5 U/mg Protein.Three different E. coli host systems, namely E. coli W 3350, E. coli ED 8654 and E. coli CSH 1, were used for the cultivation in the fermenter. The plasmid pBT 2a-1 is transformed into the corresponding competent cells. After cleaning on individual colonies, a preculture in DYT medium (Miller, Experiments in Molecular Genetics, Cold Spring Harbor, 1972, 433) containing 20 μg / ml ampicillin is grown overnight at 37 ° C. The fermentation medium (DYT) is mixed with the Inoculated pre-culture (inoculum 1%) and growing for 20 to 30 hours without selection for plasmid preservation at 37 ° C. After 25 hours the creatinamidino hydrolase activity is approximately 600 U / g wet weight or 4.5 U / mg protein.

Für die Fermentation von Pseudomonas putida wird das Plasmid pBT 306.16 in kompetente Zellen des Stammes 2440 wie vorher beschrieben, transformiert, wobei man PS putida DSM 3147 erhält.For the fermentation of Pseudomonas putida, the plasmid pBT 306.16 is transformed into competent cells of the strain 2440 as previously described, whereby PS putida DSM 3147 is obtained.

Nach Reinigung von Einzelkolonien wird eine Vorkultur in DYT Medium, das 200 ug/ml Streptomycin enthält, bei 30 ° C über Nacht inkubiert. Das Fermentationsmedium (DYT) wird beimpft (Inocculum 1 %) und die Kultur 20 bis 30 Stunden bei 30 ° C wachsen gelassen. Die Aktivität nach 25 Stunden beträgt ca. 220 U/g Feuchtmasse bzw. 1,8 U/mg Protein.After purification of individual colonies, a preculture is incubated in DYT medium containing 200 μg / ml streptomycin at 30 ° C. overnight. The fermentation medium (DYT) is inoculated (inoculum 1%) and the culture is allowed to grow at 30 ° C. for 20 to 30 hours. The activity after 25 hours is approx. 220 U / g wet weight or 1.8 U / mg protein.

Claims (14)

1. Process for the production of a micro-organism of the species E. coli or Pseudomonas putida which constitutively forms creatinamidinohydrolase, characterised in that DNA from Pseudomonas putida
a) is limitedly digested with Eco RI and a 5.8 Kb fragment is obtained or
b) is cleaved with Eco RI and Pvu II and a 2.2 Kb fragment is obtained,
the fragment obtained according to a) or b) is cloned into a vector cleaved with the same restriction endonuclease(s), this is transformed into an E. coli or P. putida strain suitable for the selected vector and the constitutively creatinamidinohydrolase-forming clones isolated.
2. Process according to claim 1, characterised in that one cleaves the plasmid pBR 322 with Eco RI, introduces the 5.8 Kb fragment into the cleavage position and transforms the plasmid obtained into E. coli.
3. Process according to claim 1, characterised in that one cleaves pBR 322 with Eco RI and Pvu II, isolates the 2.3 Kb fragment and links with the 2.2 Kb Eco RI-Pvu II fragment from P. putida with the formation of the plasmid pBT 3-2 which one transforms into E. coli.
4. Process according to one of claims 1 to 3, characterised in that one selects the transformed E. coli according to ampicillin resistance.
5. Process according to claim 3 or 4, characterised in that one treats the pBT 3-2-containing transformed E. coli cells at the point of time of the amplification of the plasmid with nitrosoguanidine, thereafter isolates the plasmid therefrom, again transforms into E. coli cells, possibly repeats this cycle and obtains the plasmid pBT 2a-1 from the clones with especially marked creatinamidinohydrolase activity.
6. Process according to claim 5, characterised in that one cleaves the plasmid RSF 1010 with Pvu II, ligates into the so obtained cleavage position the 1.4 Kb DNA fragment split from the plasmid pACYC 177 cleaved with Hae II, whereby one obtains the plasmid pBT 306.1, cleaves this with Pvu I and Sma I, ligates the 10 Kb fragment formed with the 2.8 Kb fragment which one obtains by cleavage of pBT 2a-1 with Pvu I and Pvu II, and obtains the plasmid pBT 306.16.
7. Process according to one of claims 1 to 6, characterised in that clones formed of the transformed strains are contacted with agarose plates which contain creatine, sarcosine oxidase, peroxidase and an H202 colour indicator system and those clones are selected which bring about the strongest coloration.
8. Process according to claim 7, characterised in that, as H202 colour indicator system, one uses 4-aminoantipyrine in combination with N-ethyl-N-(sulphoethyl)-3-methylaniline salt.
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UA6152A1 (en) 1994-12-29
CZ279427B6 (en) 1995-04-12
EP0187138A3 (en) 1988-03-23
US4861717A (en) 1989-08-29
DE3684787D1 (en) 1992-05-21
SK278079B6 (en) 1995-12-06
EP0187138A2 (en) 1986-07-09
IE58794B1 (en) 1993-11-17
DK3086D0 (en) 1986-01-03
ES8704543A1 (en) 1987-04-16
ATE74964T1 (en) 1992-05-15
AU561319B2 (en) 1987-05-07
ES550669A0 (en) 1987-04-16
AU5163185A (en) 1986-07-10
SU1523055A3 (en) 1989-11-15
JPH06233687A (en) 1994-08-23
YU204985A (en) 1992-09-07
JPS61162170A (en) 1986-07-22
DE3500184A1 (en) 1986-08-14
JPH07102140B2 (en) 1995-11-08
CZ7586A3 (en) 1994-11-16
GR853154B (en) 1986-04-24

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